Pneumatic warning system



R. l.. VAN wlNKLE 3,269,352

PNEUMATIC WARNING SYSTEM Original Filed Dec. 26, 1962 Aug. 30, 1966INVENTOR RY L. VAN WNKLE .BY A

ATTORNEY United States Patent O 3,269,352 PNEUMATIC WARNING SYSTEM RoyL. Van Winkle, Edmond, Okla., assignor to The Geolograph Company,Oklahoma City, Okla., a corporation of Oklahoma Original applicationDec. 26, 1962, Ser. No. 247,142, now Patent No. 3,223,068, dated Dec.14, 1965. Divided and this application Oct. 13, 1965, Ser. No. 495,601 1Claim. (Cl. 116-65) This appl-ication is a division of my copendingapplication, Serial No. 247,142, tiled December 26, 1962, now Patent No.3,223,068. This invention relates generally to a pneumatic warningsystem adapted to operate in conjunction with recording or indicatingapparatus. More speciiically, it relates sto an adjustable pneumaticwarning system that may be set to provide a warning at desired values ofa measured variable.

In the past, it has been possible to obtain warning systems forpneumatic apparatus that will provide satisfactory service provided thatthe system can be pre-set at a given value and provided, further, thatit does not require subsequent adjustment lor frequent changes of thevalue at whi-ch the warning is to be sounded. Perhaps the greatestdifficulty encountered has been the development of a warning system ofsuiiicient simplicity that it can be adjusted to a certain value of ameasured variable and then changed, by a relatively unskilled person, toprovide a warning at a different, but desired value of the measuredvariable.

It is, therefore, one object of this invention to provide an improvedwarning system lfor use with pneumatic apparatus wherein the system canbe easily adjusted to a pre-selected value of 1a measured Variable.

Another object of this invention is to provide an improved warningsystem that can be easily adjusted Iand will sound an alarm upon anincrease above or decrease below a pre-selected value of a measuredvariable.

Generally, this invention contemplates .a warning system that includeswarning means, adjustable means for controlling the value at which thewarning means will be actuated, and control means adapted to produce avisual indication of the value at which the adjustable means willactuate.

Other, further, and additional objects and advantages of the inventionwill become more apparent when the following description is read inconjunction with the accompanying drawing which is a schematic diagramillustrating a warning system, constructed in. accordance with theinvention, connected with a pneumatic recording apparatus and adapted toprovide an alarm above a certain value and below a certain value of ameasured variable.

Referring to the drawing in detail, there is shown a pneumatictransmitter 24 connected by a conduit 36 to a recording servo mechanism22. The transmitter is also connected by a condu-it to a source of airwhich is regulated to p.s.i. in a conventional manner (not shown per se)as indicated by the reference numeral 26, the latter numeral also beingemployed throughout this application to designate ya 20 p.s.i. source ofair pressure wherever required. The transmitter is also connected bymeans of element to a variable Whose condition is to be measured by theservo 22 and whose maximum or minimum condition is to be indicated bythe warning system described herein. For example, the element 25 couldbe an arm connecting with a float (not shown) resting on the surface ofdrilling mud (not shown) in a mud pit (not shown). In such an instance,the transmitter 24 would have therein a rotatable element movable inresponse to the pivoting motion of the element 25 and would be adaptedto produce an output 3,269,352 Patented August 30, 1966 ICC ' pit leveltransmitters.)

Various other types of transmitters can be utilized, the exact typedepending upon the variable to be measured. One requirement, however,for the transmitter to be used in the warning system disclosed herein isthat the transmitter 24 should have an output pneumatic pressurevariable between 3 and 15 p.s.i. which is a function of the measuredVariable.

The recording servo mechanism 22 fwill, of course, be compatible Withthe particular type of transmitter 24 employed. Briefly stated, however,a 20 p.s.i. reference pressure is introduced to the servo 22 from thesource 26 referred to above. The variable signal between 3 and 15 p.s.i.is also introduced to the servo 22 through the conduit 36. The internaldetails of the servo are such that the indicating portion thereof Willbe moved to a position dependent upon the value of the variable inputsignal through the conduit 36. (A suitable servo has been found to be aTaylor Servomatic Motor, l' series, as illustrated in catalog 4B20l,issue 2, of the Taylor Instrument Company 'TP-618.)

The transmitter 24 is also connected by means of a conduit 41 to aselector valve 40 which, as will hereinafter appear, is used forcalibration purposes. The conduit 41 lis in communication with a conduit64 through the selector valve 4t)y when the latter provides a ilow pathas indicated by the arrow A. Conduit 64 connects upwardly to an on/otfvalve 66 and through a conduit 72 to a relay 14. Conduit 64 connectsdownwardly to an on/oli valve 68 and through a conduit 70 to a relay 20.Gages 44 and 46 are connected to the conduits 72 and 70 respectively.Relay 14 is connected by means of conduit 52 to the upper end of ashuttle valve 48, the latter being essentially a two-way check valve.Relay 20 connects by means of conduit 54 to the opposite end of theshuttle valve 48. The output of the Vshuttle valve 48 is connected to abooster relay 50` which, in turn, is connected by a conduit 30 to analarm 16 (indicated as a horn). The rig air supply 38 also connects withthe booster relay 50.

The selector valve 40 is connected to an adjustable regulator 62 bymeans of a conduit 56.

Relay 14 is an adjustable snap-acting relay of the type disclosed inlt/linneapolis-I-I'oneywe'll Regulator Company bulletin -2554, publishedlune 7, 1960. Relay 14 is a direct-acting relay as will hereinafterappear. Relay 14 is provided with an integral calibrated indicatingportion 13 4and an external adjusting knob 15. A pointer 17 which isslidable along the indicating portion 13 is moved by .rotation of theadjusting knob 15.

Relay 20 is another `snap-acting relay which is essentially the same asthe relay 14, but is reverse-acting as 'will hereinafter appear. Relay20 has an integral calibrated indicating portion 19, an externaladjusting knob 21 and a pointer 23 which lis movable across thecalibrated portion 19in response to rotation of the knob 21.

As indicated above, the relay 14 is a direc-t-acting relay, which meansthat this relay will be energized or opened when the pressure in theconduit 72 exceeds a predetermined value; below this pressure, the relay14 will remain closed. Contrariwise, the relay 20 is a reverseactingrelay in that it will not be energized or opened until the pressure inthe conduit 70 drops below a predetermined value; .above thispredetermined value, the relay 20 will remain closed. It will be nowassumed that the element 25 on the transmitter 24 is a iioat armconnecting with a float (not shown) resting on the surface of thedrilling mud in `a mud pit (not shown). With the system being connectedin the manner shown, if the level in the mud pit drops below apredetermined value, the signal in the conduit 72 will increase so as toopen or energize the relay 14. When the relay 14 is energized, pressurewill be transmitted through this relay into conduit -52 to the shuttlevalve 48. The pressure in the conduit will move 'the shuttle valve insuch a manner as t-o prevent pressure being transmitted through theshuttle valve int-o the conduit 54. Thus, the pressure transmitted tolthe shuttle valve will pass through the booster relay into conduit 30to the alarm 16 or, more precisely, actuation of the booster relay `asthe result of the pressure transmitted to it from the shuttle valve,will permit passage 4of air from the rig air supply 38 through thebooster relay 50 t-o the conduit 30 and to the alarm 16.

Conversely if the level in the mud pit rises above a predeterminedvalue, the signal in the conduit 70 will decrease so as -to open orenergize the relay 20. Resulting pressure in the conduit 54 will movethe internal mechanism (not shown) of the shuttle valve in the oppositedirection to prevent communication with the conduit 52. Thus, pressurepasses fr-om the shuttle valve 48 in lthe same manner as described aboveto the booster relay so Vas to actuate the alarm 16.

The selector valve 40, gages 44 and 46, valves 66 and 68, and adjustableregulator 62 are provided for the purpose of Calibrating the relays 14and 20. The dials on the gages 44 and 46 are calibrated in advance tocorrespond with the units of measurement of the measured variable (notshown) which operates the transmitter 24. Thus, if transmitter 24 isused in a mud pumping system, for example, then gages 44 .and 46 will becalibrated in units of liquid level. Valve 40, for example, is movableinto two positions Ito permit flow in two direc- -tions indicated byt-he right-angled .arrows designated by the reference characters A andB, of course, at separate periods of time.

Now, if it is desired to calibrate relay 14, the valve 66 is left open,valve 68 is closed, and selector valve 40 is placed in -a llow conditioncorresponding to arrow B. Thereafter, the control on adjustableregulator 62 is adjusted until the pressure reading on the gage 44corresponds to the first desired value (or level) of the variable whosecondition is sensed by the transmitter 24. When the gage 44 is broughtto the correct or desired value, the adjustment knob on the relay `14 ismoved until the alarm '16 is sounded. The relay 14 is now adjusted to4operate for the condition corresponding to the reading on the gage 44.Thereafter, the valve 66 is closed and valve 68 is opened. Now, thecontrol on the adjustable regulator 62 is adjusted until the pressurereading on the gage 46 corresponds to the second desired value (orlevel) of the variable. The relay is then adjusted in the same manner asdescribed above with respect to relay 14.

Although the invention set forth herein has been described in terms ofchanges in liquid level, the condition being sensed by the transmitter24 need not necessarily be a liquid level. Indeed, it can be a variablepressure, hydraulic or pneumatic or it can be a variable mechanicalmovement, either rotary or translational. It can be a change in weightor volume. Practically no limitations should be placed upon the type ofvariable to which the present invention can be adapted. Just so long asthe transmitter 24 is capable of producing an output pressure variablebetween 3 and 15 p.s.i., the systems described herein will be completelyoperable. It is well known in the art that there are many differenttypes of transmitters or converters which are adapted to change avariable pneumatic pressure, liquid pressure or mechanical movement intoa corresponding variable pneumatic pressure. Thus, the selection of aparticular transmitter depends upon the type of variable bein-gmeasured.

Wherea-s the present invention has been described in particular relationto the drawing attached hereto, it should be understood that other andfurther modifications, apart from those shown or suggested herein, maybe made within the spirit and scope of this invention. For example, thepressure range of the pneumatic signal has been described as beingbetween 3 and 15 p.s.i. and the input operating pressure range of theservos has been described as being between 3 and 15 p.s.i. It should beunderstood that the applicant does not intend to limit this invention toany particular range, the above being disclosed merely for the sake ofpreference and in the interest of completeness of disclosure. Actually,any predetermined range can be employed just so long as the samepredetermined range is used in a uniform manner. Likewise, the specicoper-ating pressures, such as 20 p.s.i., are not at all critical, butobviously depend upon the requirements and versatility of the unitswhich these pressures operate.

What is clai-med is:

A warning system for indicating when the value of a given variable fallsbe-low a tirst predetermined value and exceeds a second predeterminedvalue comprising a sensing means adapted to sense the instantaneousvalue of said variable and to transform the same into a correspondingoutput pneumatic pressure falling within a predetermined range ofpneumatic pressures, a recording device connected to the output of saidsensing device for recording the instantaneous value of said variable, aselector valve having two inlets and a single outlet, one inlet beingconnected to the output of said sensing device and the other inlet ofsaid selector Valve being connected to the outlet of a regulator valve,said regulator valve having an inlet connected to a source of |airpressure, said selector valve being adjustable to place said iirst andsaid second inlets alternately in communication with the outlet of saidselector valve, a pair of on/oi valves each having an inlet and anoutlet, the outlet of said selector valve being connected in common tothe inlets of said on/oi valves, the rst on/otf valve having its outletconnected to a rst pneumatic gage, a rst pneumatic relay having itsinlet connected to the outlet of said rst on/ 01T valve, said -firstpneumatic relay having an outlet tand ibeing normally closed but beingadapted to open to provide communication between its inlet and outletwhen the pneumatic pressure transmitted to said -rst relay from saidsensing means falls below said rst predetermined value, the second on/oft valve having its outlet connected to a second pneumatic gage, asecond pneumatic relay having its inlet connected to the outlet of saidsecond on/off valve and having an outlet which will be placed incommunication with said inlet when said second relay is opened, saidsecond pneumatic relay being normally closed but being opened when thepressure transmitted to said second relay from said sensing meansindicates that the instantaneous value of said variable exceeds saidsecond predetermined value, a twoway check valve having two inlets and asingle outlet with its inlets being connected to the outlets of saidpneumatic relays, respectively, an alarm device connected to the outletof said two-way check valve, said rst relay having means adjusting thesame to change the pressure required to open said relay, and said secondrelay having means adjusting the same to change the pressure required toopen said relay.

References Cited by the Examiner UNITED STATES PATENTS 3,138,956 6/1964Falbout et al. 73-316 LOUIS J. CAPOZI, Primary Examiner.

